When I use a mixer (Behringer 4-track), the instructions say to wait about ~30 seconds after turning off the phantom power before unplugging anything. They say not doing that could damage the equipment.

Now I have an XLR-to-USB connection that provides phantom power (48V, like the mixer), and there's nothing about that in the instructions. Is it safe to unplug the mike right away?

2 Answers
2

In general, if you unplug anything from a power amp, you could amplify small currents into a pretty loud pop...which could be enough to damage speakers or amplification circuits.

With phantom power, the problem is that when you unplug, the power to circuits is dropped quickly so you get current surges from inductors and capacitors, and these can be much higher than a simple pop.

The only reason I can think of to have to wait before unplugging your mic is to allow any capacitors to drain. I don't believe this can take more than about five seconds. I have always waited about this long anyway since that's how long it takes me to reach up and grab the mic to pull the cable out after turning off phantom power. By convention I prefer pulling the cables out of the mic first, then the preamp.